Incandescent-lamp filament.



G. R. HOLMES. NCANDESGENT LAMP PILAMENT. APPLICATION FILED MAY e, 1909. RBNBWED JUNE 124, 1911. A f l n" V4 iylylf Patented Jan. i6, 1912.

@bww/wanner though the loops and 26 are shown as angularin section it is not essential that these should be angular. They may be circular in form,v as shown in Fig.- 6. These loops are located as shown in Fig. l in radial planes.

Referring to Figs. Lt and; designatesl the bulb attached to the usual base or socket 3l, provided with a central support 32 widened out so as to form a central filament support. 33 of large diameter. The leading-1n wires 34, 35 lead in through the support 32 and are connected with the conductor which is composed' of alternate scctions of iron wires 36 and platinum or other metallic wires 37, 3S, 39 connected in series. :Ihese platinum Wires', as shown in Fig. 4, are of different lengths. A central support 40, attached to 32 and 33, is provided with a number of anchor wires '41 for supporting the different filaments. In this type of .lamp the entire lilame'nt'is split up into a large number of loops in this case twentyY or more) all connected in series. -By giving the filaments the -construction shown 1n "Figs 4 and 5 I have found that the bestresults 4are produced.

In the claims the term conductor is leadin -in Wires and in this case includes both t e iron and platinum sections. It is :belaste to be noted that the iron sections perform a different function from the ordinary leading-1n wires. I n this case they increase the actual resistance of the conductor itselfand are not used primarily as connectors between the filament and the lamp base as is the case with the leading-in Wires.

lli/'hat I claim is:

l. A filament for electric lamps,r` co1n- ,posed of an elongated conductorV corrugated port and anchor arms radiating therefrom,

a filament composed of an incandescing conductor shaped so as to forma plurality of outwardly facing nearly closed loops, said anchor arms engaging the loops.y In testimony whereof I atlix myl signature in presence -of two witnesses.

. -GWYLLYM R. HOLMES.

IVitnesses:

IRENE GONTRUM, J. Cron. KNoUss. 

